scsi: ufs: ufs-qcom: Fix ESI null pointer dereference

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: scsi: ufs: ufs-qcom: Fix ESI null pointer dereference ESI/MSI is a performance optimization feature that provides dedicated interrupts per MCQ hardware queue. This is optional feature and UFS MCQ should work with and without ESI feature. Commit e46a28cea29a ("scsi: ufs: qcom: Remove the MSI descriptor abuse") brings a regression in ESI (Enhanced System Interrupt) configuration that causes a null pointer dereference when Platform MSI allocation fails. The issue occurs in when platform_device_msi_init_and_alloc_irqs() in ufs_qcom_config_esi() fails (returns -EINVAL) but the current code uses __free() macro for automatic cleanup free MSI resources that were never successfully allocated. Unable to handle kernel NULL pointer dereference at virtual address 0000000000000008 Call trace: mutex_lock+0xc/0x54 (P) platform_device_msi_free_irqs_all+0x1c/0x40 ufs_qcom_config_esi+0x1d0/0x220 [ufs_qcom] ufshcd_config_mcq+0x28/0x104 ufshcd_init+0xa3c/0xf40 ufshcd_pltfrm_init+0x504/0x7d4 ufs_qcom_probe+0x20/0x58 [ufs_qcom] Fix by restructuring the ESI configuration to try MSI allocation first, before any other resource allocation and instead use explicit cleanup instead of __free() macro to avoid cleanup of unallocated resources. Tested on SM8750 platform with MCQ enabled, both with and without Platform ESI support.

References

• https://git.kernel.org/stable/c/aaf17a35a59572c8b29372883619c3dbb0ebb50a
• https://git.kernel.org/stable/c/6300d5c5438724c0876828da2f6e2c1a661871fc